Joseph hires a math tutor to help him operate his CAS. The tutor charges him $20, plus an additional $10 per hour. a)Construct a rule for the cost of the tutor b)Construct a graph for the cost of the tutor versus the additional rate per hour. c)If Joseph hires his math tutor for 3 and a half hours during the week, how much does he owe?

a)Construct a rule for the cost of the tutor. Let n = number of hours Let C = the cost of the tutor Find the fixed cost and additional charge per hour Fixed cost = $20 Additional charge = $10 per hour ∴ C = 10n + 20

b)Construct a graph for the cost of the tutor versus the additional rate per hour. State the rule for a straight liney=mx+c Substitute in for the equation found in part a) C=10n+20 Write down the values for m and c m = 10, c = 20 ∴ the gradient = 10, and the y intercept = 20

c)If Joseph hires his math tutor for 3 and a half hours during the week, how much does he owe? C = 10n + 20 Substitute in the number of hours for n C=10(3.5) + 20 C = C = 55 ∴ the cost for three and a half hours of tutoring is $55